Retort-furnace.



N. H. FREEMAN.

RBTORT PUB-NACE.

APPLICATION FILED Dnc. 1e, 1907.

Patented Feb. 15, 1910.

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N. H. FREEMAN.

RETORT FURNAOB.

APPLICATION FILED 1120.16, 1007.

Patented Feb. 15, 1910.

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l Hofr/nm NAT I-I. FREEMAN, OF BOULDER, COLORADO.

RETORT-FURNACE.

Specification of Letters Patent.

Application filed December 16, 1907.

Patented Feb. 15, 1910.

Serial No. 406,645.

To all whom it may concern:

Be it known that I, NAT H. FREEMAN, a citizen of the United States,residing at Boulder, in the county of Boulder' and State of Colorado,have invented certain new and useful Improvements in Retort-Furnaces;and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the letters and figures ofreference marked thereon, which form a part of this specification.

My invention consists of a furnace in which the metallic values arerecovered from their ores by fusion, the pulverized ore being introducedinto the lower portion of a mass of molten metal and caused to travel upthrough the metal whereby all fusible values are reduced to a moltenstate and unite with the mass of molten metal within the retort. Theretort is ineased and is heated in any suitable manner whereby theoriginal contents of the retort are kept in a molten conditionnotwithstanding the introduction thereto of the ores whose metallicvalues are to be recovered.

As shown in the drawing a rotatable conduit is suspended in the retortand upon it is mounted disks whose outer peripheries or edges extendnearly to the walls of the retort. Every alternate disk is provided withopenings located near the conduit through which the material as itpasses upwardly through the molten mass, is caused to travel. Everyother alternate disk is free from openings and the material passingupwardly through the molten mass must pass around the outer edges of thelast named disks or between their edges and the wall of the retort. Byvirtue of this construction the material fed to the retort and passingupwardly therethrough is obliged to take a zigzag course. During thisupward travel the metallic contents of the ore are reduced to a moltenstate while the non-fusible ash gathers on to of the molten mass and isremoved by s immer blades or arms which are attached to the rotatableconduit above the disks. These disks also serve as agitating deviceswhereby the pulverized material is distributed through the molten mass.The material is fed into the bottom of the retort by a worm or feedscrew located in the rotatable conduit, the screw being rotatedindependently of the conduit.

Having briefly outlined my` improved construction, I will proceed todescribe the same in detail reference being made to the accompanyingdrawing in which is illustrated an embodiment thereof.

In this drawing, Figure 1 is a vertical longitudinal section takenthrough my improved furnace. Fig. 2 is a horizontal section taken on theline 2-2 F ig. 1 looking downwardly. Fig. 3 is a top plan view in detailillustrating one of the disks mounted on the rotatable conduit.

The same reference characters indicate the same parts in all the views.

Let the numeral 5 designate what I will term a retort adapted to containa mass of molten metal as lead. This retort may be approximately full ofmolten metal at the beginning of the operation. The retort is suspendedwithin a casing G having a lire brick lining 7 surrounded by an outerwall 8 which may be composed of metal. As shown in the drawing theretort is approximately cone-shaped, with the point of the conelowermost. Its upper edge is provided with a circular ilange 9 whichrests upon the upper edge of the fire clay lining 7 of the casing. Thisflange 9 is clamped in place by means of a cover 10 which rests on topof the retort and also overlaps an exteriorly projecting horizontallydisposed llange 12 formed on the outer wall of the casing. Above thecover 10, is located a spider 13. The outer portion 11 of this spider,is connected with the disk 10 and the llanges 12 by means of bolts 15 towhich are applied nuts 1G. The spider inside of its outer portion 14,projects upwardly above the cover 10 and its central web 17 is providedwith an opening through which passes a centrally located sleeve orconduit 18 having a funnel-shaped mouth 19. IVithn this conduit 18 islocated a feed screw 2O whose spiral thread 21 fits closely within theconduit. The cover 10 is provided with an opening registering with theopening in the web 17, through which the rotatable conduit passes.Attached to the sleeve 1.8 and located within the retort 5, is located anumber of disks which diminish in size from top to bottom, in order toharmonize with the general construction of the retort as heretoforeoutlined.

y the spider 13.

As shown in the drawing the disks which are devoid of openings aredesignated A, B and C respectively, while those provided with openingsare designated D, E, and F. The openings in the last named disks aredesignated Gr. Each disk above the lowermost is provided with a hub 22directly connected with the conduit 1S. Attached to the conduit abovethe uppermost disk, is a skimmer composed of a hub 23 made fast to theconduit exteriorly and having radial wings 24, for the purpose ofskimming or removing the non-fusible ash from the top of the molten massand causing it to pass outwardly through an opening in the casing bymeans of a chute or trough 25 located at the upper edge of the apparatusand extending through the upper portion of the casing.

As shown in the drawing a gas burner 4 is arranged within the casingbelow the bottom of the retort for supplying the necessary heat tomaint-ain the metal within the retort in a molten condition. This burneris connected with a supply pipe 3 provided with a valve 2.

To the upper extremity of the conduit 18, above the spider 13 a gear 26is secured by means of aset bolt 27. This gear meshes with a small bevelgear 28 fast on a shaft 29 operated from any suitable power. This shaftis journaled in a box 40 and also in an upwardly projecting part 41constituting a portion of the frame work and resting upon This shaft 29is also provided with a pinion 30 meshing with a relatively large gear31 fast on a short shaft 32. This shaft 32 is journaled in a box 33mounted on an upright 34 resting on top of the spider 13 and is providedwith a bevel pinion 35 meshing with a relatively large gear 36 fast onthe upper portion of the worm spindle. The upper extremity of thisspindle passes through a frame plate 37. Above this frame plate a disk38 is made fast to the spindle by a set bolt 39. This disk maintains theworm in a suspended position within the rotary conduit.

lhen the apparatus is in use, the material to be treated is fed througha trough or chute 42 into the funnel-shaped mouth 19 of the rotaryconduit 18. Power being applied to the shaft 29, the feed screw isrotated to carry the material downwardly through the rotary conduit anddischarge it into the bottom of the retort. Tt is assumed that thisretort is filled or approximately filled with molten metal at the'beginning of the operation. Simultaneously with the rotation of the feedscrew, a rotary movement is also imparted to the conduit 18 togetherwith its disks. This rotation of the conduit maintains the materialwithin the re tort in a state of agitation and facilitates theintermingling of the' pulverized ore with the molten mass. vThispulverized material after entering the bottom of the retort, passesupwardly through the molten mass in a zigzag path as indicated by thearrows in F ig. 1. During this Aupward movement, the metallic values ofthe ore are reduced to a molten condition while the non-fusible ashcollects on top of the molten mass and is removed therefrom by theskimmer blades 24 and caused to pass out of the retort through thetrough 25.

The casing is provided near its bottom with o-penings 43 for theentrance of atmospheric air. This casing is also provided with upperopenings 44 to maintain a circulation of atmospheric air within thecasing in order to supply the fuel gas with the necessary oxygen forpurposes of combustion. The fumes from the retort are carried awaythrough a conduit 45 which may be connected with a stack.

During the operation of the apparatus, the metal in the material to betreated as it becomes molten, unites wit-h the already molten masswithin the retort and increases its volume. Hence provision must be madefor 'drawing off the molten metal from the retort in order to preventits overflow through the ash trough 25. To this end the lower extremityof the retort is provided with an opening 45 with which is connected aconduit 46 thro-ugh which the molten material may be drawn off eitherconstantly or at intervals as may be desired.

It is intended that the disks D, E and F having the openings G, shouldhave their outer edges or peripheries practically in contact with theinner surface of the retort, in order to compel the material to take thezigzag course heretofore described. In the drawing these disks are shownas close to the inner wall of the retort as is practicable withoutbringing them in actual rubbing contact therewith.

Having thus described my invention, what I claim is:

A retort furnace, comprising an inverted cone-shaped,molten-metal-containing receptacle, a plate secured to the top thereof,a conduit passing through the top plate of the receptacle and projectingdownwardly near the bottom thereof, its extremities being open, theconduit being ournaled in the said top plate and provided with disksarranged thereon, one above the other, and suitably separated, eachalternate disk having its periphery close to the wall of the retort, andbeing provided near the conduit with o-penings, the other alternate diskbeing free from openings, suiicient space being left between their outerperipherie's and the inner surface of the retort to allow the materialto travel between the disks and the wall of theretort, and means forintroducing ore in pulverized form into the bot-tom of the retort,through the said conduit, a feed screw being located within the conduitand mounted to the skimmer blades, substantially as derotateindependently on the latter, and scribed. 19 skimmer blades to removethe ash, the said In testimony whereof I aflix my signature blades beingconnected with the upper exin presence of two witnesses.

tremty of the conduit and arranged to 1o NAT H. FREEMAN.

tate therewith, the retort being provided at VitneSSeS: its top with anoutlet for the ash as it is re- L. A. EWING, moved from the top of themolten mass by l FRED. G. FoLsoM.

